Fuel-feed for carbureters



A. G. McCALEB. v FUEL FEED FOR CARBURETERS. APPLICATION mso JAN.19. 191s.

1,33 1,445. Patented Feb. 17, 1920.

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FUEL-FIEED FOR QARIBURETER Specification of Letters Patent.

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Application filed January 19,1916. Serial no. races.

To all whom it may concern: I

Be it known that I, ALBERT G. McCALnB, a citizen of the United States, residing at Chicago, in the county of Cook and State of Illinois, have invented a certain new and useful Improvement in Fuel-Feed for Carbureters, of which the following is a full, clear, concise, and exact description, reference being had to the accompanying drawings, forming a part of this specification.

My invention relates to oarbureters for internal combustion engines and primarily it has for its object the provision of simple and inexpensive means for supplying or feeding the carbureter with fuel from a reservoir located below the level at which fuel is supplied to the cabureting or vaporizing chamber of the carbureter.

Tn attaining the objects of my invention as described in this specification I provide means for assuring that each time the supply of available fuel in the float chambpr forming a part of the carbureting device falls below the proper level a diflerence in pressure exists between the float chamber and the supply reservoir. Communication between the supply reservoir and the float chamber is provided so that the supply of fuel in the float chamber is replenished from the reservoir supply.

The instrumentalities and arrangement of parts whereby this and other incidental objects of my invention are attained are fully set forth in the following detailed description wherein reference is made to the accompanying drawings in iwhich,

Figure 1 illustrates a conventional carbureter equipped to accomplish the objects of my invention.

Fig. 2 is a fragmentary view generally similar to Fig. 1, but illustrating a modified form of fleet chamber and valve mechanism;

and

Fig. 3 illustrates a form of float chamber and valve mechanism which may, if desired, .be substituted for the. float chambers of Figs. 1 and 2.

Similar characters of reference refer to similar parts throughout the several vlews.

Referring first to Fig.1, the 'carbureter ,in

casing indicated at 10 isprovided with the usual flange 11 tofacilitate the connection of" the carbureter with the manifold, or intake passage, of the internal combustion engine with which the carbureter is associated.

provided with a float The casing 10 provides the carbureting or vapor1z1ng chamber 12. At 13 is illustrated .an inclosed float chamber from which fuel is supplied directly to the vaporizing or carbureting chamber 12 through the usual fuel nozzle 14. Pivoted within the carbureter casing 10 and located posterior to the carbureting or vaporizing chamber 12 is a throttle valve 15.

As will more fully hereinafter appear, in order to secure the most satisfactory results it is desirable-that under running conditions the pressure within the carbureting or vaporizing chamber 12 benot permitted to be less than a certain pre-determined and relatively low pressure. lnerder to secure this end the air inlet port 16 is normally closed by a valve 17 coiiperating with valve seat 18. The valve illustrated in the drawings is provided with a stem 19 passing through a central aperture in a spider 20. Carried at the free end of the stem 19 and threaded thereon is an adjusting nut 21 and interposed between the nut 21 and the spider 20-is a helical spring 22. The spring 22 is arranged so as to permit the opening of the valve 17 only after a relatively low pressure reduction has been created within the carbureting, or atomizing, chamber 12, say, for instance, a pressure reduction a-trifle'greater than one pound. The carbureting chamber is provided with a port 23 for the admission of auxiliary air, this port being normally closed by a valve 24 006 eratin with avalve seat 25. The stem 26 of the va vs 24 is conveniently guided by a spider 27 and interposed between the spider 27 and the inner face of the valve 24 is a helical spring 28 which normally retains the valve 24 upon its seat. The helical spring 28 is of such strength as to permit the opening of the valve 24 to admit auxiliary air only after thevalve 17 has opened in response to the pro-determined pressure reduction created Within the carbu'reting chamber 12, as previously described.

The float chamber 13 of the carburetor is 29 conveniently guided by a post 30 extending into a central openg 31 formed in the float. At 32 I have illustrated the supply tank, or reservoir,

located-below the level of the fuel within the float chamber 13. The supply of fuel contained within the tank, or reservoir, 32 is subjected to atmospheric pressure through retained in closed position.

and the carbureter float chamber.

illustrated this valve as mounted upon a lever 37 pivoted at 38 and having the free instance,

a vent in the top of the reservoir illustrated at 33. At 34 I haveillustrated a conduit which leads from the reservoir 32, desirably from a point near the bottom thereof, and terminates in the float chamber 13 at a polnt above the normal level of the fuelcontained within the latter. At 36 is illustrated a valve which when in closed position shuts ofl communication between the I'QSGIWiOifi' 32 ave end of the longer arm thereof connected with the upper end or the top of the float 29. The connection between the lever 37and the float 29 may conveniently be a pin and slot connection, as illustrated in the drawin s.

An aperture is tapped in the wall of the carbureting chamber 12 adjacent the float chamber 13 and threaded into said aperture is a plug, or nut, 39 having formed therethrough a passage of relatively small cross section, this passage being indicated by the reference numeral 40. It will be seen that .the passage 40 when open affords pneumatic connection between the carbureting chamber 12 and the space in the float chamber above the level of the fuel therein. The passage 40 is, however, arranged to beclosed by a needle valve 41 carried by the shorter arm of a lever 42, which lever is pivotally mounted at 43, and the longer arm of which has pin and slot connection with the to of the float 29, as illustrated. When the oat chamber 13 contains the requisite quantity of fuel the float assumes the position illustrated in Fig. 1 and, therefore, the valves 36 and 41 are When, however, the fuel within the float chamber drops below the requisite level the lowering of the float causes the valves 36 and 41 to be opened and establishes communication between the float chamber and the carbureting chamber and communication between the float'chamher and the fuel tank or reservoir. As previously mentioned, the float chamber 13 is normally closed against communication with the atmosphere Formed in the top of the float'chamber is an aperture 44 normally closed by a valve 45 seating against pressure.

from. the atmosphere. A helical spring 46 acting between the top of the float chamber and an adjusting nut 47- threaded upon the free end of the valve stem 48 normally retains the valve 45in closed position. The.

valve 45 is designed to permit communication between the float chamber and the atmosphere onlyafter a pre-determined pres.- sure reduction has been created in the space above the fuel in the float chamber, say, for

a pressure reduction of approximately one pound. I have found that a one pound pressure reduction in the chamber 13 1s sufiicient to raise the fuel through a disqnodified form of float chamber tance of approximately 30 inches which is sufficient for most purposes where the carbureter is-used in connection with an automobile engine. When, therefore, it is desired to operate the system on a one pound pressure reduction the valve 45 is arranged just described anterior valve 17 will opento supply air to the 'carbureting' chamber 12. It will be understood, however, that under running conditions the valve 17 never permits less pressure reduction to exist in the carbureting chamber 12 than the one determined upon. The fuel nozzle 14 suppliesthe necessary liquid fuel to the carbureting' chamber during the operation of the carbureter and the auxiliary air valve 24 comes into play to supply the necessary q antity of air when the requirements of the engine are such that auxiliary air be furnished to the carbureting chamber. -When the level of the fuel within the float chamber 13 falls below the proper point the droppin'g of the float'29, acting through the levers 37 and 42, serves to open the valves 36 and 41. When this occurs the communication afforded through the passage 4O assures a pressure reduction of at least one pound Within the float chamber 13. This reduction of pressure in the .float chamber 13 causes liquid fuel to be drawnthrough the conduit 34 and past the valve 36 until the fuel in the float chamber has again attained the proper level whereupon the con sequent rising of the float 29 serves to close the valves 41 and 36 thus preventing the further flow of fuel from the reservoir 32 to the float chamber and shutting ofl? communication between the float chamber and the carbureting chamber, through the-passage 40. It will be understood that the valve 45 acts to prevent the suction of the engine from creating a pressure reduction substantially greater than one pound within the float chamber 13.

- In Fig. 2 I have illustrated mechanism. A number of the parts of this modified float chamber mechanism are similar in'all.

respects to the corresponding parts describedin connection with Fig. 1 and to these parts I have, therefore, applied the same reference characters with the addition of the leta' slightly eena-es ter a. it will be noted that in the form of apparatus shown in Fig. 2 communication between the carbureting chamber and the upper portion of the float chamber is provided by a passage i9 which terminates in an aperture 50 located substantially over the center of the float 29 The aperture 50 is provided with a conical seat arranged to cooperate with a needle valve 51 projecting upwardly from the top of the float 29 It will be understood that the needle valve 51 serves to close the opening 50 when the requisiteamount of liquid fuel is contained within the float chamber 13*. The operation of the mechanism as shown in Fig. 2 is substantially like the operation of the mechanism illustrated in Fig. 1.

In Fig. 3 the same reference characters as in Fig. l have been applied to corresponding parts, the letter I) being added to each such reference characters. Attention is directed to the fact that the float 29 of Fig. 8 is provided with two tandem chambers 52 which may be provided with a suitable lining 53. The fuel nozzle 14' has communication with the float chamber through a passage 5% and a tube 55, the upper end of which extends into the smaller diameter chamber 52 formed within the float 29 Formed in the tube 55 is a plurality of apertures 56 which permit communication between the float chamber and the space within the tube 55. contains the requisite quantity of fuel the float 29 assumes the position shown in the drawing. It will be understood that the apertures 56 are located sufficiently far away from the lower end of the smaller diameter chamber 52 to permit the normal rising and falling of the float to open and close valves 36 and 41* without shutting oif the free passage of fuel through the openings 56. Extending through the top of the float chainber 13 is a stem 57, the lower end of which is disposed slightly above the highest position of the float 29". )A spring 58 normally retains the stem 57 in the position shown. The stem 57 carries a stop 59 which serves to seal the space between the stem 57 and the wall of the aperture through which the stem extends. When in the operation of the carbureter it is desired to'supply the carbureting chamber with a relatively large quantity of liquid fuel the stem 57 is depressed, thereby carrying the float downwardly until the apertures 56 are brought opposite the walls of the smaller chamber 52 of the float. After this occurs further downward movement of the float serves to force When the float chamber 13 liquid fuel through the tube 55, passage 54:, and the nozzle is into the. carbureting chamber. The levers 37 and e2 have such pin and slot connection with the upper end of the float 29 as to permit this downward movement of the float to prime the carbureter'. it will be understood that the quantity of fuel forced through the nozzle li in the manner described may be varied by changing the size of the chambers 52 and tube 55, and by changing the position of the apertures 56 along the tube 55.

Having thus described my invention what I claim as new and desire to secure by Letters Patent of the United States is:

l. The combination with a carbureter comprising a carbureting chamber having air inlet and combustible mixture outlet ports, a float chamber in proximity to the carbureting chamber, means for furnishing fuel to the carbureting chamber from the float chamber, a float in said float chamber, a passage leading from the carbureting chamber to the float chamber above the fuel therein, a fuel inlet for the float chamber located above the normal level of fuel therein, said fuel inlet adapted to be connected with a fuel reservoir wherein the level of fuel is lower than the normal level of fuel in the float chamber, a valve controlling the passage between the float chamber and the car-bursting chamber, a valve controlling said fuel inlet and meansconnecting each of said valves with the float, whereby said valves are opened when the fuel in the float chamber falls to a certain level, and closed when the level of the fuel in the float chamber is at a certain higher level.

2. In a carbureter, a carbureting cham her, a float chamber in proximity thereto, a float in the float chamber, a nozzle in the carbureting chamber fed from said float chamber, a fuel inlet for the float chamber, a valve for closing the same, a passage connecting the float chamber and carbureting chamber, a valve for closing the same, and connections between the float and each of said valves whereby the valves are opened when the level of fuel in the float chamber drops below normal;

In witness whereof,'1 hereunto subscribe my name this 17th day of January, A. D. 1916.

ALBERT G. McCALEB.

Witnesses MARY A. Coon, KATHLEEN W. HU'I'TON. 

